Pavement marking pattern and method

ABSTRACT

The invention pertains to pavement marking patterns and the application thereof to roads, streets, walkways and the like. Various pattern marking designs replicate bricks, cobblestones, horizontal signage, logos and other components. The marking patterns are composed of two or more independent sections, the first section is a grid representing for example, the mortar joints in a brick wall. The second sections or inserts, for example represent bricks which are contained within the grid. As the first and second sections are generally formed from different colored, preferably thermoplastic materials, a hot melt adhesive spray is utilized on the bottom surface of the marking pattern bridging the intersections between the first and second sections, maintaining the integrity of the marking pattern for convenience during handling and application to a substrate. Preferably the hot melt spray adhesive has approximately the same softening point range as the pattern sections for heat treatment during application.

PRIORITY

This application is a continuation of and claims priority under 35U.S.C. §120 of original U.S. patent application Ser. No. 12/592,462entitled “Pavement Marking Pattern and Method”, filed on Nov. 25, 2009,which is a continuation of U.S. patent application Ser. No. 10/816,635entitled “Pavement Marking Pattern and Method”, filed on Apr. 2, 2004,granted Jan. 12, 2010 as U.S. Pat. No. 7,645,503. This referencedapplication is also hereby expressly incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The invention herein pertains to markers for pavement and particularlypertains to pavement marking patterns utilizing two or more independentsections which are sprayed with an adhesive to maintain the integrity ofthe pattern prior to its application to a substrate.

BACKGROUND OF THE INVENTION

In recent years increasing numbers of municipalities, office complexes,shopping centers and other commercial developments have utilizedthermoplastic pavement markings with various patterns and designs toguide, decorate and protect high traffic areas such as highways,pedestrian crosswalks, parking lots and business entrances. A typical,conventional pavement marking pattern as set forth in PCT applicationUS/03/03156 (WO03/064771 A1) consists of a preformed planarthermoplastic sheet or strip having a thickness of approximately 0.01″(2.5 mm). The width of these patterns vary with the purpose of themarking Such patterns may include a first section or grid, for exampleto represent the mortar joints in a “brick” design and a plurality ofsecond sections or “bricks” which are coplanar therewith, usually in acolor different from the mortar color. The second section or brickswhich are separately manufactured are inserted into the first section orgrid before application of the pattern to the pavement. Various such twosection marking patterns are commonly available such as: herringbone,standard brick, cobblestone, paving slabs and many other designs.Marking patterns with more than two sections are also commonly availablesuch as horizontal highway and street signage, logos and many others.

As hereinbefore mentioned, these marking patterns consist of two or moreindependent sections which must be carefully assembled and handledbefore applying to pavements such as asphalt, concrete or other suitablesubstrates. These marking patterns are placed at desired locations suchas road crosswalks, intersections, parking lots or other sites. In somecases heat is then applied to soften the pavement marking patterncausing it to firmly adhere to the substrate. Various adhesives can alsobe used to adhere the marking pattern to the substrate.

While the purchase of such pavement marking patterns is relativelyinexpensive, much time and labor is devoted to the assembly andapplication of the pattern to the substrate. Most patterns consist oftwo or more sections which are independently formed for manual assemblyat the job site and time and effort is needed to assemble and maintainthe integrity of a pattern before the heat treatment. Usually thepattern placed on the substrate must be moved manually for adjustmentpurposes. During such movement, the independent sections in the patterninadvertently become unaligned, requiring reinsertion or realignment. Ifthe realignment is not precisely accomplished, the marking pattern willhave lost its integrity and the entire pattern must be removed manuallyfrom the substrate, the substrate cleaned and a second attempt at theapplication made with the reinserted or new marking pattern. Thisre-application results in extra time, labor and materials. In the past,to maintain the integrity of the marking pattern before the heattreatment and during the handling and placement, “spot adhesives” havebeen used which remain somewhat “tacky” after being applied to thebottom of the patterns at the grid intersections to maintain patternintegrity. However, these small adhesive circles or “spots” aregenerally a different type of polymer than the marking pattern and canprevent proper attachment and easy movement of the marking pattern onthe substrate at the spot adhesive locations before and during the heatapplication of the marking. Also, certain spot adhesives are notcompatible with the plastic materials from which the patterns are formedand can cause the pavement marking sections to separate from thesubstrate after the heat application, as only a weak bond is formed withthe substrate.

Thus with the problems and difficulties associated with maintaining theintegrity of the pavement marking patterns during handling andapplication at the job site, the present invention was conceived and oneof its objectives is to provide an improved pavement marking pattern inwhich the pattern sections are properly connected during handling andinstallation on a selected substrate. It is another objective of thepresent invention to provide a relatively inexpensive pavement markingpattern having two or more sections in which the sections are joined byuse of an applied adhesive.

It is yet another objective of the present invention to provide a methodfor forming a pavement marking pattern which allows cost efficientfactory assembly of the pattern and which prevents dislodging andseparation of the pattern sections during handling, transportation andapplication.

It is still another objective of the present invention to provide anadhesive which can be conveniently sprayed onto the back of pavementmarking patterns which will sufficiently adhere thereto and preventseparation of the sections during handling, and not deteriorate the bondbetween the pavement marking pattern and the substrate.

It is still another objective of the present invention to provide amethod for easy application of the adhesively sprayed marking pattern tothe substrate.

Various other objectives and advantages of the present invention willbecome apparent to those skilled in the art as a more detaileddescription is set forth below.

SUMMARY OF THE INVENTION

The aforesaid and other objectives are realized by providing aconventional pavement marking pattern formed of a thermosetting orthermoplastic having two or more sections, manually joined by bridgingthe bottom surface thereof with an adhesive having substantially thesame temperature softening point as the sections of the marking pattern.The adhesive is sprayed primarily along the intersections of the patternto cover a percentage (approximately 5-90%) of the pattern bottomsurface area while bridging the intersections. The more intricate thepattern (with more joints or intersections), the greater the percentageof coverage required. The spray adhesive can be a typical polyamide, EVAbased hot melt adhesive or other and preferably consists of a hot meltpolyamide resin based adhesive which is sprayed in a circular or spiralstring like configuration at a temperature at or above its softeningpoint. The sprayed hot adhesive strikes the marking pattern and adheres,bridging and bonding the pattern sections to maintain pattern integrityduring subsequent handling. Uni-Rez 2633 as sold by Arizona ChemicalCompany of P.O. Box 550850, Jacksonville, Fla. 32225 is the mainingredient in the preferred hot melt adhesive. The preferred hot meltadhesive is formulated with Uni-Rez 2633, ester modified rosins,fillers, extenders, levelers and other conventional components.

In a typical manufacturing process, various sections of a pavementmarking pattern (such as a brick and mortar pattern) are factoryassembled and while in assembled form, the bottom of the pattern issprayed with the hot melt adhesive described above using preferablyspray gun model: Hysol-175-spray as manufactured by Loctite Corporationof 1001 Trout Brook Crossing, Rocky Hill, Conn. 06067, having variouspressures and nozzle settings to select from, depending on the viscosityof the particular adhesive employed. A circular or spiral string-likeadhesive configuration is preferred for the spray.

Once the sprayed hot melt adhesive has cooled, the grid and inserts aresuitably bridged and joined and the pavement marking pattern is packagedfor shipment. Upon receipt at the job site, the packages are opened andafter the intended substrate, usually asphalt or concrete is properlycleaned and swept, the marking pattern is then placed on the substratewithout concern of disassembly during handling, movement and adjustment.Once suitably placed, a heat application is delivered from aconventional source which softens the marking pattern and the underlyingsprayed adhesive, both of which have the approximate same temperaturesoftening point to thereby affix the pavement marking pattern to thesubstrate. Time and labor are thereby saved as the marking patternsections have been adhered to form a unified pattern by the hot meltadhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 pictures a top view of a partially assembled pavement markingpattern with one brick exploded therefrom;

FIG. 2 demonstrates a bottom plan view of the brick pavement markingpattern as shown in FIG. 1 fully assembled;

FIG. 3 illustrates in schematic form a spray application of the adhesiveto the bottom of the brick pavement marking pattern as seen in FIG. 2;

FIG. 4 depicts an enlarged sectional view of the pavement markingpattern as shown in FIG. 3 with the adhesive applied;

FIG. 5 features the bottom of the pavement marking pattern as seen inFIG. 3 after a typical spray adhesive application is completed;

FIG. 6 shows a schematic pavement marking pattern during standardsubstrate; and cross-sectional view of the initial installation.

FIG. 7 presents the final installation step of the pavement markingpattern on the substrate with a propane torch heater.

DETAILED DESCRIPTION OF THE INVENTION

For a better understanding of the invention and its operation, turningnow to the drawings, FIG. 1 illustrates a typical partial decorativepavement marking pattern 10 for application to concrete, asphalt orother suitable substrates. Marking pattern 10 is a brick and mortarpattern used herein for illustration purposes but as would be understoodvarious other thermosetting and thermoplastic patterns are commerciallyavailable such as 90° herringbone, cobblestone, pavement slabs,horizontal signage, logos and other designs. Also, while many colors areavailable for the pavement marking patterns, typically differentsections of each pattern are of different colors, such as a “light” gridor mortar color and a “darker” brick or insert color. The markingpatterns typically consist of two or more sections.

Preferred marking pattern 10 shown for demonstration purposes consistsof two separate thermoplastic sections, first section 11 represents agrid or mortar joint and second section 12 represents a brick or insert.Sections 11 and 12 are generally formed independent of each other due tothe differences in color. Pavement marking pattern 10 is planar and isconventionally formed from a standard thermoplastic.

Once marking pattern 10 has been conventionally formed and assembled asshown in FIG. 2, with bottom 15 of marking pattern 10 facing upwardly,the preferred method steps of the invention are as follows:

Marking pattern 10 is now ready for the adhesive application as seen inFIG. 3 whereby preferably Loctite spray gun 20 receives adhesive 25which is forced or pumped from tank 21 through conduit 22. Adhesive 25is then sprayed by using compressed air which passes through hose 26 anddirected onto bottom 15 of marking pattern 10. Adhesive 25 is a hot meltpolyamide resin based adhesive, preferably composed from Uni-Rez 2633available from Arizona chemical, delivered at an elevated temperature ofapproximately 127°-210° C. in a semi-solid condition thereby formingspiral strings 27 on marking pattern bottom 15.

As shown enlarged in FIG. 4, strings 27 bridge across first grid sectionII, intersections 18 and second insert sections 12. Upon cooling to roomtemperature strings 27 harden and bond first section 11 and secondsection 12 forming unified marking pattern 10A. The area covered byadhesive strings 27 may range from 5-90% of the total marking patternbottom 15 surface area, depending on the complexity of the particularpattern design. In FIG. 5 the bottom of preferred unified markingpattern 10A is shown with an approximate 30% adhesive area coveragewhich is preferred for this marking pattern.

The preferred method of applying marking pattern 10A to a desiredsubstrate such as asphalt 30 shown in FIG. 6 can be described asfollows. Preferred marking pattern 10A having adhesive strings 27 bondedthereto is first unrolled or positioned onto cleaned and swept asphaltor concrete 30. Once unrolled or positioned, marking pattern 10A is thenmoved and shifted for precise placement without fear of patterndisassembly. After suitable placement, marking pattern 10A is thenheated with conventional heat torch 35, shown schematically in FIG. 7whereupon marking pattern 10A and adhesive strings 27 are softened dueto their similar or approximate softening points thus resulting in asecure, permanent adherence of marking pattern 10A to asphalt 30. Thepreferred softening point range for both adhesive strings 27 and markerpattern section 11 and 12 is 90°-120° C. although other thermoplasticmaterials may be used having different softening points. Additionalmarking patterns are subsequently similarly applied as necessary for thedesired coverage of the particular substrate.

While the preferred adhesive and pavement marking patterns herein areformed of thermoplastic resins, thermosetting resins could also be usedbut are not preferred such as epoxies or other organic oligomeric orpolymeric materials. Such thermosetting adhesive would require a highmolecular weight to generate a melt viscosity sufficient to function asa “string spray” adhesive as described above. Such melt viscosity wouldrange from approximately 500 to 100,000 cps with a preferred range of1500-2000 cps, as are commercially available

The illustrations and examples provided herein are for explanatorypurposes and are not intended to limit the scope of the appended claims.

We claim:
 1. A method of applying a pavement marking pattern havingcontiguous sections to a substrate comprising the steps of: a) forming apavement marking pattern consisting essentially of: an independentthermoplastic grid section and a plurality of independent thermoplasticinsert sections, wherein each of said plurality of insert sectionsresides within said grid section and said plurality of insert sectionsare coplanar, and wherein said grid section and said plurality of insertsections both comprise a planar top surface and planar bottom surfacethat are coplanar to each other, b) adhering said plurality of gridsections such that said grid sections are in direct contact with each ofsaid plurality of insert sections thereby forming intersections betweensaid grid section and each of said plurality of insert sections, c)adhering said pavement marking pattern to said substrate by spraying apolyamide adhesive backing layer on said coplanar bottom surface in acircular or spiral configuration crossing said intersections, whereinsaid sprayed polyamide adhesive has a softening point of between 105 and120 degrees C. and wherein said adhesive is applied at a temperatureabove said adhesive's softening point such that said adhesive covers5-90 percent of said coplanar bottom surface.
 2. The method of claim 1wherein adhering the marking pattern to the substrate comprises the stepof heating the marking pattern.
 3. A method of making a pre-bondedpavement marking pattern comprising: a) providing an independentthermoplastic grid section and a plurality of independent thermoplasticinsert sections, wherein each of said plurality of insert sectionsresides within said grid section and said plurality of insert sectionsare coplanar, and wherein said grid section and said plurality of insertsections both comprise a planar top surface and planar bottom surfacethat are coplanar to each other, adhering the plurality of grid sectionssuch that said grid sections are in direct contact with each of saidplurality of insert sections thereby forming intersections between saidgrid section and each of said plurality of insert sections, and sprayinga polyamide adhesive backing layer on said coplanar bottom surface in acircular or spiral configuration crossing said intersections, whereinsaid sprayed polyamide adhesive has a softening point of between 105and120 degrees C. and wherein said adhesive is applied at a temperatureabove said adhesive's softening point such that said adhesive covers5-90 percent of said coplanar bottom surface.